package lib.grasp.widget.decoration;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import androidx.core.view.ViewCompat;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import android.view.View;

/** 线 */
public class DecorationLine extends RecyclerView.ItemDecoration
{
    private static final int[] ATTRS = new int[]{android.R.attr.listDivider};

    public static final int HORIZONTAL_LIST = LinearLayoutManager.HORIZONTAL;
    public static final int VERTICAL_LIST = LinearLayoutManager.VERTICAL;

    private Drawable mDivider;
    private int mOrientation;

    private int mPadding = 0;

    public DecorationLine(Context context, int orientation)
    {
        final TypedArray a = context.obtainStyledAttributes(ATTRS);
        Drawable d = a.getDrawable(0);
        mDivider = d;
        a.recycle();
        setOrientation(orientation);
    }

    public DecorationLine(Drawable d, int orientation)
    {
        mDivider = d;
        setOrientation(orientation);
    }

    public void setPadding(int padding)
    {
        this.mPadding = padding;
    }

    public void setOrientation(int orientation)
    {
        if (orientation != HORIZONTAL_LIST && orientation != VERTICAL_LIST)
        {
            throw new IllegalArgumentException("invalid orientation");
        }
        mOrientation = orientation;
    }

    @Override
    public void onDraw(Canvas c, RecyclerView parent)
    {
        if (mOrientation == VERTICAL_LIST)
        {
            drawVertical(c, parent);
        }
        else
        {
            drawHorizontal(c, parent);
        }
    }

    public void drawVertical(Canvas c, RecyclerView parent)
    {
        final int left = parent.getPaddingLeft();
        final int right = parent.getWidth() - parent.getPaddingRight();

        final int childCount = parent.getChildCount();
        for (int i = 0; i < childCount; i++)
        {
            final View child = parent.getChildAt(i);
            final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();
            final int top = child.getBottom() + params.bottomMargin +
                    Math.round(ViewCompat.getTranslationY(child));
            final int bottom = top + mDivider.getIntrinsicHeight();
            mDivider.setBounds(left + mPadding, top, right - mPadding, bottom);
            mDivider.draw(c);
        }
    }

    public void drawHorizontal(Canvas c, RecyclerView parent)
    {
        final int top = parent.getPaddingTop();
        final int bottom = parent.getHeight() - parent.getPaddingBottom();

        final int childCount = parent.getChildCount();
        for (int i = 0; i < childCount; i++)
        {
            final View child = parent.getChildAt(i);
            final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();
            final int left = child.getRight() + params.rightMargin +
                    Math.round(ViewCompat.getTranslationX(child));
            final int right = left + mDivider.getIntrinsicHeight();
            mDivider.setBounds(left, top + mPadding, right, bottom - mPadding);
            mDivider.draw(c);
        }
    }

    @Override
    public void getItemOffsets(Rect outRect, int itemPosition, RecyclerView parent)
    {
        if (mOrientation == VERTICAL_LIST)
        {
            outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());
        }
        else
        {
            outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);
        }
    }
}
